Mizar Phosphorus In Phosphate Mining, To Pressure Behavior And Supporting Technology

According to geologic condition and mining test in Guizhou Kaiyang Phosphorite Mine, the primary way to improve safety and quality is selecting a method of mining. The support technology and roof management is the most important part in mining. The oblique belt method, small segment avalanche method, room and pillar mining method and flood peak mining method have been put into practice since 1958. In order to increase output, Large no-track equipments have been introduced since 1986. The separate empty cavity with anchor-staff shoring roof method was applied that solve undersurface mining successfully. But because of the special geologic conditions of the middle phosphorite, a new problem in safety and losing at mining middle phosphorite appear and must be solved.This paper studies activities of underground pressure and methods of roof control, and analyzes mining method and support technics with theory nalyses and in situ monitoring and tests, which includes concretely l)comments synthetically on geology of the mine and mining technical conditions;2)studies tectonic stress, the stress in wall rock and fracture zone in the middle phosphorite, and analyzes instability of roof supported by rock bolt;3) analyzes fracture mechanism, underground pressure, tunnel layout and mining method, and finds reasons of laws of deformation and fracture of tunnel wall rock;4)carries out tests on the various supports of roof in Kai Lin mine area, and compares open stoping in the condition of the roof being supported by rock bolt and crest truncation mining method, consequently considers crest truncation mining method is a more feasible mining method.The results of the research have been successfully applied in layout and mining of the middle phosphorite.